error: Package ‘inginious-0.3a2.dev0’ in /var/lib/gc-of-borg/.nix-test-rs/repo/38dca4e3aa6bca43ea96d2fcc04e8229/mr-est/30606/pkgs/servers/inginious/default.nix:69 is marked as broken, refusing to evaluate.

a) For `nixos-rebuild` you can set
  { nixpkgs.config.allowBroken = true; }
in configuration.nix to override this.

b) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add
  { allowBroken = true; }
to ~/.config/nixpkgs/config.nix.

(use ‘--show-trace’ to show detailed location information)